Lens-grinding apparatus



Sept. 4, 1923. l;467.160 H H. w. HILL LENS GRINDING APPARATUS Filed Nov. 25, 1920 INVENTOR HARRY w. HILL l BY ATTORNEYS Patented Sept. 4, 1923.

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HARRY w. HILL, or SoUTHBarneE, MASSACHUSETTS, Ass-xenon To AMERICAN OPTICAL COMPANY, OF SOUTHBRIDGE TION OF MASSACHUSETTS.

, MASSACHUSETTS, A VOLUNTARY AsSocIA LENS-GRINDING APPAR US,

Application filed November 23, 1920. Serial No. 426,007.

T all whom it may concern:

Be it known that I, I'IARRY W. HILL, a citizen of the United States, residing at Southbridge, in the county of Worcester and State of Massachusetts, have invented certain new and useful Improvements in Len s Grinding Apparatus, of which the following is a specification.

Thisinvention relates to improvements in factorily employed in the new manner withreference to the following specification taken in connection with the accompanying drawings, and it will be understood that I may make any modifications in the specific details shown and described within the scope of the appended claims without departing from or exceeding the spirit of my invention.

Figure I is a side view of a grinding machine embodying my improvements.

Figure II is a plan view of one of the lens holders complete.

Figure III represents a bottom plan view thereof.

Figure IV is a perspective view of the old block previously known in the art.

Figure V is a perspective view of my attachment for use in connection with my block.

Figure VI is a sectional view taken as on the line VI-VI of Figure II.

Prior to my invention it has been customary in the manufacture of ophthalmic lenses to make use of a grinding tool 1 suit ably ro'tat-ably supported and engaging one surface of the lenses 2. To enable the lenses to be properly supported in connection with the grinding tool use has been made of what is termed in the art a block, which is shown in Figure IV of the drawings, comprising the skirt or body portion 3 of substantially the shape on the under side as the'lens sur face to be secured thereon and having rising therefrom the central neck portion 4 socketed as at 5 to receive the pin 6 of a grinding machine. Prior to my invention considera-' ble time and labor has been necessary during the operations heretofore employed in grinding lenses, thereby adding to the expense of manufacture of such goods, slowing up production and increasing the liability of breakage of the partially manufactured product due to the frequent handlings.

It is, therefore, the purpose of my inven tion to get away from these difficulties of the prior art and at the same time to make it possible to utilize the known mechanism of the prior art without substantial change,

thus rendering the installation of my improvement a ready and economical affair. To accomplish this result I preferably provide a spring clamp or spider shown in detail in Figure V. This device as illustrated comprises a collar portion 7 with radially extending spring arms 8. The collar 7 is formed slightly less in diameter than the outside diameter of the neck 4 on the lens block so that the same may be forced down over the neck and when in position will have a tight fit therewith, securely connecting the parts without the necessity of the employment of solder, rivets or other fastening devices. The-spring arms 8, as will be best understood by reference to Figures V and VI, have the downwardly deflected portions 9 extending over the sides of the lens block 3 and terminating in outwardly deflected or flaring end portions 10, against which the lens is pressed as it is moved toward the block, pressure of the lens serving to cam these ends outwardly so that the detent portions 11 of the spring arms will i clampingly engage the edges of the lens and securely hold the lens in place upon the 7' be securely held in position during the grinding operation. when the grinding and polishing has been completed it is merely necessary to press the lens away from the block, when it will snap out without the necessity of chilling the parts or loosening the adhesives. The lens will come away clean without the necessity of special operations to remove adhering portions of the adhesive. It will thus be seen that I have provided an efficient device for mechanically securing lenses to lens blocks which is capable of use with either new or old structures and which will be extremely eiiicient for the intended purpose.

I would call particular attention to the fact that with my improved construction as illustrated undue or distortive spring pressure is not required, since the fit of the lens against the block and the pressure against the grinding tool will normally hold the parts together, while the pressure between these parts as the grinding operation takes place, coupled with the pressure of the spring fingers against the edge of the lens produces more "friction than the friction between the socket 5 and pin 6 so that there is no liability of the lens twisting with respect to the block, the fact being that the block will rapidly spin on the point 6 as a center when the device is in use.

I claim:

1. A lens block comprising a support for the lens and a plurality of spring fingers carried by the support for resiliently engaging the edge of a lens to secure the latter in position.

2. The combination with a lens block of a spider carried by the block and having resilient arms extending down over the edges of the block into engagement with the lens to retain the lens in place.

3. An attachment for a lens block co1n-- prising a collar member having a plurality of radially extending arms terminating in downwardly deflected gripping portions, said gripping portions terminating in outwardly deflected ends, and being provided with detents immediately adjacent said ends for grippingly engaging the edge of a lens.

In testimony whereof I have atlixed my signature, in presence of two witnesses.

HARRY XV. HILL.

Witnesses.

ALICE G. I-IAsKELL, Es'rrrnn M. LAFLER. 

